Why do I get a segfault in C from declaring a large array on the stack?

Question

I get a segfault from this line of code:

int fatblob[1820][286][5];

Why is that?

Answer 1

int fatblob[1820][286][5];

you are trying to allocate a memory location of 180*286*5*4 (let size of int = 4) that is around 9.8 MB, so there is a possibility of having lesser default stack size on your OS.

LINUX has 8192 KB(i.e. 8 MB) of stack size. So obviously you will be getting a stack overflow if you are trying to allocate more memory on stack.

You can try changing the stack size of your OS. In LINUX you can try ulimit

ulimit -s < whateversize you want it to be>

like

$ ulimit -s 1024

I hope it will help you.